Multiple myeloma (light chain disease) with rheumatoid-like amyloid arthropathy and mu-heavy chain fragment in the serum

A Case of μ Heavy and λ Light Chain Amyloidosis in a Patient With Bi-Clonal (IgM κ and λ) Gammopathy Treated With Daratumumab

Our case report is of an elderly male with a history of IgM κ lymphoplasmacytic lymphoma (LPL) presenting with generalized neuropathy and weakness. Due to his LPL history and worsening renal function, he underwent a renal biopsy revealing the presence of μ heavy and λ light chains, revealing a diagnosis of amyloidosis with unbound heavy & light chains (AHL), a rare type of amyloidosis. His bone marrow biopsy demonstrated κ light chain restriction by flow cytometry and amyloid deposition. The patient's serum had elevated free κ and λ light chains with a free light chain (FLC) ratio of 3.17. Serum immunofixation was positive for IgM κ and λ light chain clones. He completed six cycles of cyclophosphamide, bortezomib, dexamethasone, and rituximab (CyBorD+R), normalizing the FLC ratio. Still, he continued to present with persistently elevated M protein, IgM κ, and λ light chains on immunofixation. Thereafter, daratumumab, a human monoclonal antibody directed against CD38 expressed on myeloma cells was initiated, which led to a negative immunofixation study after two cycles accompanied by a reduction in protein excretion in the urine. The patient achieved a complete hematological response with daratumumab. To date, our case is the only reported μ heavy and λ light chain amyloidosis patient with bi-clonal (IgM κ and λ) gammopathy to be successfully treated with daratumumab.

Mu heavy chain disease with MYD88 L265P mutation: an unusual manifestation of lymphoplasmacytic lymphoma

Background

Mu heavy chain disease is a rare lymphoid neoplasm characterized by vacuolated bone marrow plasma cells and secretion of defective mu immunoglobulin heavy chains. The biological basis of mu heavy chain disease is poorly understood.

Case presentation

We report a case of mu heavy chain disease with MYD88 L265P mutation and deletion of 6q, genetic aberrations that are both strongly associated with lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Identification of the truncated mu immunoglobulin was facilitated by mass spectrometric analysis of the patient’s serum.

Conclusions

Mu heavy chain disease has been described as similar to chronic lymphocytic leukemia; however, the frequency of lymphocytosis in mu heavy chain disease has not been previously reported. We reviewed all previously published mu heavy chain disease reports and found that lymphocytosis is uncommon in the entity. This finding, along with the emerging genetic feature of recurrent MYD88 mutation in mu heavy chain disease, argues that at least a significant subset of cases are more similar to lymphoplasmacytic lymphoma than to chronic lymphocytic leukemia.

μ-Heavy Chain Disease Associated with Systemic Amyloidosis

mu-heavy chain disease (HCD) is very rare, with only 30 cases reported in the literature. We report a patient with mu-HCD associated with systemic amyloidosis. The diagnosis of mu-HCD was based on findings of mu-heavy chain fragments in the serum, Bence Jones proteinuria and vacuolated plasma cells in the bone marrow. To our knowledge, this is the third case in which systemic amyloidosis led to the patient's death.

Successful treatment of mu-heavy chain disease with fludarabine monophosphate: a case report

Heavy chain diseases (HCD) are monoclonal lymphoproliferative disorders of B-cells characterized by the synthesis of truncated heavy chains without associated light chains. In patients with mu-HCD, which is a very rare form of HCD, neoplastic cells produce immunoglobulin M heavy chain. The prognosis for patients with mu-HCD is poor, and there is no specific treatment for mu-HCD. In this report, we present a patient with mu-HCD accompanied by splenomegaly and thrombocytopenia. We treated this patient with the fludarabine monophosphate therapy we use for patients with B-cell chronic lymphocytic leukemia. After 5 courses of fludarabine monophosphate treatment, the splenomegaly and thrombocytopenia improved. Fludarabine monophosphate therapy may be a new strategy to improve the prognosis of patients with mu-HCD.

High frequency of amyloid lymphadenopathy in uremic patients

Amyloid lymphadenopathy has only been reported in case report form, or in small groups of patient groups within large series. We believe that amyloid lymphadenopathy is common in uremic patients, and thus designed this study to determine the frequency of this condition in hemodialysis patients, and to assess its types and patterns. We reevaluated 46 uremic patients' lymph node biopsies for amyloid deposits. We also immunohistochemically identified the protein origin of these deposits using Amyloid A, kappa, lambda, beta2 microglobulin, and transthyretin antibodies. Histopathologically, we observed for vascular involvement, follicular deposition, and diffuse deposition. We detected amyloid deposits in 10 of the 46 (22%) patients' lymph nodes. The patterns of deposition were vascular involvement alone in six specimens, vascular involvement plus follicular deposition in three, and vascular involvement plus diffuse deposition in one specimen. Amyloid AA type protein was present in seven nodes, beta2 microglobulin-related amyloid in two nodes, and immunoglobulin-derived protein (AL) in one node. We assessed these 10 patients for causes of end-stage renal disease (ESRD) and other conditions that might relate to amyloidosis. The cause of ESRD in the seven patients with AA amyloid were renal amyloidosis secondary to Familial Mediterranean Fever in four, glomerulonephritis in one patient who had bronchiectasis and Castleman's disease, unknown in one patient who had bronchial asthma, and pyelonephritis in one patient who had no characteristics that could be linked with AA type amyloidosis. The causes of ESRD in the two individuals with beta2 microglobulin-related amyloidosis who had been on long-term hemodialysis were pyelonephritis and glomerulonephritis. The cause of ESRD in the patient with AL type protein was glomerulonephritis, and this patient had no systemic disease. We conclude that amyloid lymphadenopathy is, indeed, common in uremic patients. Amyloid type AA is the most prevalent form of amyloid protein in uremic patients, but amyloid type does not always correspond with underlying cause of renal failure, or with the presence of systemic disease.

Extraction of amyloid-like fibrils from chronically inflamed periodontal tissues

Immunohistological studies have established an association between the deposition of the amyloid P protein and disease status in chronically inflamed periodontal tissues. The aim of this study was to determine if amyloid-like fibrils could be extracted from these tissues. Biopsies were homogenised and extracted exhaustively in saline before serial extraction in distilled water. Electrophoretic analysis revealed the presence of previously undetected protein bands in the fifth water extraction. These were probed and were found to react with antisera to kappa and lambda immunoglobulin light chains but not with antisera to mu, gamma or alpha heavy chains. Electron microscopic study indicated fibrils of 9.7 nm diameter. These bound Congo Red and exhibited green birefringence under polarised light. The results supported the presence of an amyloid-like matrix composed of immunoglobulin light chains in the lesions of chronic periodontitis. This could explain the persistence of foci of degenerate plasma cells and the paucity of granulation tissue formation in the disease process.

Mu-heavy chain disease: presentation as a benign monoclonal gammopathy

mu-Heavy chain disease (HCD) is a rare monoclonal lymphoid disorder characterized by the failure to assemble a complete IgM immunoglobulin. The mu-heavy chains analyzed to date revealed absence of the variable region and a shortened constant domain. We report the first case of mu-HCD presenting as a benign monoclonal gammopathy. The literature on the 27 reported mu-HCD cases is reviewed, and important clinical and laboratory findings are discussed. The ages of the patients ranged from 15 to 80 years (median, 57.5 years). Twenty-two of 27 patients had an associated lymphoplasma cell proliferative disorder. A monoclonal spike on routine serum protein electrophoresis was found in only 8 of 19 patients. Fourteen of 22 patients had Bence Jones proteinuria, but mu-HCD protein was reported in the urine of only two patients. The survival ranged from less than 1 month to 11 years (median, 24 months).

Systemic amyloid arthropathy associated with multiple myeloma

This is the first report of an autopsy case of systemic amyloid arthropathy associated with multiple myeloma in Japan. The patient was a 72-year-old male who had been suffering from multiple myeloma (IgA-lambda) with extensive arthropathy of the systemic joints. Autopsy examination revealed severe deposit of amyloid in the articular cavities of the systemic joints showing a feature of amyloidoma. Furthermore, numerous amyloid deposits were found in the wall of small blood vessels in the major organs. In the bone marrow, there were many atypical plasma cells and foamy cells both showing positive reaction for IgA and lambda light chain. No such atypical cells were observed in the other organs except for the bone marrow.

Clinicopathological importance of deposits of amyloid in the femoral head

The pattern of amyloid deposits in the femoral head is described in four cases, two of which had deposits of amyloid related to age and two of which had generalised systemic amyloidosis (one of primary amyloidosis, one of multiple myeloma). The deposition of amyloid in the articular cartilage of the femoral head was similar in all four cases. Heavy deposits of synovial amyloid were identified in the case with primary amyloidosis and in one of the cases with amyloidosis related to age. Both cases of generalised systemic amyloidosis showed abundant deposits of amyloid in the bone marrow. Amyloid was not present in the bone marrow of either case with amyloidosis related to age. The importance of these findings is discussed in relation to the pathogenesis of the arthropathy syndrome of a rheumatoid type described in cases of primary amyloidosis and multiple myeloma.

Amyloid in osteoarthritic hip joints: deposits in relation to chondromatosis, pyrophosphate, and inflammatory cell infiltrate in the synovial membrane and fibrous capsule

The relationship between osteoarthritic change and amyloid degeneration was studied in 116 joint capsules from osteoarthritic hip joints. Twenty-seven (23%) contained amyloid deposits. Twenty-eight joint capsules showed chondroid metaplasia in the fibrous part. Significantly more amyloid degeneration was found among these. Six joint capsules contained pyrophosphate crystals. Five of these were positive for amyloid. Chronic inflammation of the joint capsule was found in 80% of the cases and was negatively correlated with amyloid degeneration, which is in good agreement with the biphasic theory for the pathogenesis of amyloid. Further investigation is necessary to decide how chondroid metaplasia takes part in the production of amyloid.

Amyloid in osteoarthritic hip joints. Depositions in cartilage and capsule. Semiquantitative aspects

Amyloid depositions in tissue from 116 osteoarthritic hip joints were examined. There was no significant correlation between amyloid and age although there was a tendency for joints from older patients to have more marked amyloid degeneration. We found significantly more amyloid in the joint capsules from male patients than from females. No difference in amyloid deposition was found between the right and left side, and pressure-loaded/less pressure-loaded parts of the femoral head contained equal amounts of amyloid. With the exception of two cases amyloid depositions in the joint capsule were always accompanied by amyloid in the joint cartilage (P less than 0.001). Conversely the cartilage was often positive when the capsule was negative for amyloid.